Pontiac: Leaky Grand Am, body seams, cracked windshield

Question
I have a 2-door 1992 Grand Am SE that in the past few months has started letting water in when it rains although I can't tell where it is coming from. The floor of the driver's side both front and back accumulate up to an inch of water. There are no holes in the floor anywhere. I replaced a cracked windshield that I thought might be to blame, along with some cracked weatherstripping around the driver's door but the problem persists.
In addition, my power locks and dome light have quit working since this problem began. Do you think there's a connection and can you give me any ideas where the water might be coming from?

Answer
The most common places for water to get in are around the bulkhead connectors and the body seams in the cowl area.
The bulkhead connectors are the large wire connectors in the firewall where the wire go from under the hood to the inside of the car. The body seams are under the panel that the wipers are on.
There is a chance that water is getting into your electrical system and causing a problem with your lights and locks.